Tensioning device



N0v.13;,1945. Q LEIHISER 2,888,982

TENSIONINGA DEVICE Filed Aug. 21, 1944 2 sheets-shea 1 Tru/e Tter:

George 1.... L ehiser,

by ,m

Nov. 13, 1945.

G. l.. LEI'THl'sER TENSIONING DEVICE Y Filed Aug. 21, 1944 2 Sheets-Sheet 2 H is At tofrwey.

vPatented Nov. 13,' 1945 PATENT OFFICE TENSIONING DEVICE George L. Leithiser, York, Pa., assignor to General Electric Company, a corporation of New York Application August 21, 1944, Serial No. 550,365

3 Claims.

This invention relates to tensioning devices, more particularly to'a tensioning device for applying a tension to a ilament, and it has for its object an improved device of this character which ments of the tensioning device. parts being broken away and parts shown in section so as to illustrate certain details o1' construction.

Referring to the drawings, this invention has is smaller and simpler in its construction than 5 been shoWn in one form as applied to a tensioning tensioning devices heretofore known, and which has improved operating characteristics..

This invention further contemplates a tensioning device which has considerably less weight than those heretofore generally known. This is used to tension the wire drawn to and used in a of great importance ,since it is the Weight of the device which largely determines the speed with which the associated mechanism can be operated. 'I'he lighter the weight the faster can the mechanism be operated.

This invention may be used in avariety of applications, such as for tensioning, braiding or wrapping wire that is fed to a cable armoring or braiding machine; tensioning a wire delivered to a coil winding machine, etc.

In vcarrying out this invention in one form thereof, I provide a bobbin upon which the filament or wire is wound and from which it is drawn to suitable apparatus, such as a cable armoring or device for tensioning wire which is used to armor a cable in a suitable cable armoring machine (not shown). It will be understood, of course, that it can be used for other purposes; thus, it may be coil winihng machine to wind a coil with the wire under a predetermined tension.

As shown, the tensioning 'device comprises a bobbin i0 which has a cylindrical surface Il upon which the wire ila (Fig. 1) is Wound, and atthe ends oi which are circular anges I2.

A suitable axle structure rotatably supports the bobbin l0. As shown more clearly in Figs. 3 and 5., this structure comprises axle members i3 and lll which are threaded upon the ends of a shaft -V l5. Thev member it is brazed to the shaft i5 so as to provide a secure one-piece structure. The

axle member i3 is secured in proper threaded position bymeans of a circular lock nut i 6. A simibraiding machine, particularly to the braiding V lar nut il at the other end of the shaft i5 is rigpoint. Mounted Within the spool are a plurality of plates arranged to be moved into frictional engagement with eachother. One of the plates is non-rotatably secured to an axle which supports the spool, but which may be moved longitudinally along the axis of the axle, while the other is attached in a similar way to the spool.

A control arm for the plates is located exteriorfr ly of the spool and is arranged to be moved -replate sponsively to variations in tension in the filament being drawn from the spool: when the tension attains a predetermined maximum value the arm is moved to release the plates and thereby permit the spool to, rotate so that a part oi' the lament idly secured to the member I li.

Rotatably mounted upon lthe two axle members it and it is a cylindrical memberl or sleeve i8 which at its right-hand end is provided with a ball race i@ upon which are seated ball bearings'2llthe axle It being provided with a complementary seat 2i for the balls. The left-hand end of the sleev'e it is mounted for rotary motion with reference to the axle i3 through a member 22. As shown, the sleeve i8 and the member 22 have cooperating ball bearing races 23 and 2E respectively Vin which rotate a plurality of ball bearings 25. The member 22 is provided with a second ball bearing race 2t vopposite a race -21 on the axle i3 can be payed od. On the other hand, when the 40 tension falls below the desired value the arm is restored and causes the plates to move into frictional engagement to again hold the spool against rotation.l For a more complete understanding of this in- 4 and upon which races ball bearings 28 are mounted. 'Y

The cylindrical member il ofthe bobbln is mounted upon the sleevei-S. This sleeve, as shown,`is provided with circular anges 29 and 3l! at its opposite ends, and uponwhich the cylinder vention, reference should be hadv to the accompanying drawings in which Fig. l is a side elevation of tensioning apparatus arranged in accordance with this invention; Fig. 2 is a front elevation of the tensioning apparatus shown in Fig. 1; '50

Fig. 3 is a sectional view taken through a portion of the device shown in Figs. 1 an@ 2; Fig. 4 is a perspective view illustrating various elements of the tensioning device in expanded-relation; and

Fig. 5 is a perspective view illustrating certain ele- 55 il is mounted. Secured to the surface of the sleeve it between the anges 29 and 30 is a key 3i .which coacts with a suitable keyway (not shown) provided in the inner wall of the cylinder II for the purpose of securing thebobbin to the sleeve i8.

The two axle membersiand It aremounted upon a supporting base 32. This base is provided with a pair of spaced-apart upright standards 33 and t.- Secured to these two standards are a are open at the top so that the circular nuts I8 and I l can be moved into them and rotatably supported by the curved bottom walls of the two bearing seats. The bearing members are attached to the standards by means of screws lia. Attached to the nut Il is a key 30h tted to the upright walls of bearing seat 38 so as to prevent rotation oi' the axle member I4, the shaft Il and the axle mem-y 'berlt Also mounted within the sleeve I8 are suitable means for holding the spool with -a predetermined force so that the filamenti Ia which is withdrawn from the bobbin will be held under a predetermined tension. For this purpose, there are provided a plurality of spaced` friction plates 31, which are non-rotatably mounted upon the righthand axle member I I, the part of the axle upon which these plates are mounted having a no ncircular cross-section. as shown in Fig. 5, and the' plates having complementary openings iitted to this axle part. It will be observed that by reason of this arrangement the plates 31 are nonrotatable with reference to the axle Il, but they can move longitudinally with referenceto it. Interposed in the spaces between the plates l1 are a plurality of plates 38 which are non-rotatable with reference to the sleeve i8, but which may-be moved longitudinally with reference to the sleeve:

for the purpose of attaching the plates 3l to the sleeve 18,' the sleeve is provided with a plurality of longitudinal keyways 38 spaced circumferentially about its inner wall and which 'keyways are received by keys provided for them on the plates 38. The two sets of plates 31 and IB cony Y :,s'saasa pair of bearing seats 35 and Il respectively whichV screw 42 which is formed on an` in'ner extension of the member 22. as shown more clearly in Figs. 3

and 5. The nut 4I has a bore complementary to the non-circular section of the axle memberupon which the friction plates 31 are mounted, 'and thus', while it can move longitudinally, it cannot rotate. Housed within the nut is a compression spring I3 which bears against the inner end of the screw I2 and against an abutment I4 provided on the nut. The nut is made in two sections 4Bl and 45a for machining purposes, and after machining is assembled and rigidly secured together in any suitable way, as by welding.

The nut 4I and screw 42 have such a long pitch that the pressure of the compression spring 43 tends to move the nut away from the screw and thereby apply pressure to the friction plates n and 3B to restrict the movement of the sleeve 'Ihe nut 4I is operated through rotation of screw I2 by means of an arm IB which is rotatably mounted upon the bearing member $5.,

as shown more clearly in Figs. 4 and 5. Secured to this arm is a plate 41, which plate when the arm is rotated is arranged to engage a plate Il which is an integral part of the screw member 22; as shown, the plate 4B is attached directly to a collar 49 which is threaded upon and integrally united with the screw member 22. When the arm 46 is rotated clockwise, asfviewed in Figs. 1, 4 and 5, the end surface 50 of the plate Il engages the end surface 5I of the plate IB so as tov rotate the nut member 22 clockwise. This rotation of the nut member withdraws the nut 4I against the pressure of the spring 43 and'thereby releases um menen plazes a1 anaal comune sleeve n isrelessedtopemmnebobbm n m rotate. 0n the other hand, when the arm Il is rotated counter-clockwise, the pressure of the spring Il acting upon nut 4I forces the nut 4I inwardly against the plates to force them into engagement and thereby again hold the bobbin Il from rotating with a predetermined force.

Ihe arm 4l is rotated responsively to the tension in the filament IIa drawn from the hobbin. For this purpose, the arm rotatably supports one end of a spool Il, the other end of which is simi larly supported in an arm l5 which is similar` to the arm 4B, but whichy is rotatable upon the bearing member Il of standard Il. The two arms are biased in the counter-clockwise direction, as viewed in Figs. 1. and 4, by means of helical springs It. Each spring has one ,end anchored to the arm 4B, Il, and the other end anchored to upright members 33 and 34 through slotted studs l1 which are secured to upright members 3l and 3l by welding.

In the operation of the machine, it will be understood that the filament IIa from the bobbin Il passes under the roller ll and thence upwardly to the apparatus which is using the wire, the apparatus drawing the wire from the bobbin. The bobbin is held stationary by the friction plates 31 and ll when the .arm Il is in its position shown in Figs. 1 and 4. but as the tension in the iament is increased by the apparatus drawing it upwardly, the attached arms II and il are rotated clockwise, and when the arm Il attains substantially the dotted line position shown in Fig. 1, its plate I1 engages the plate IB to turn the screw 42 to move the nut 4I outwardly to release the friction plates. This frees the bobbin I0 to rotate, and a length of the filament is drawn from it.v When the tension in the filament again reduces.. the arm Il moves back to its original position underthe bias of the springs I8, and the spring-48 is released to move the nut 4I inwardly to again force the friction plates into engagement with predetermined force. In this way, successive lengths of the filament I la are drawn from the bobbin, but the length of the f lament extending from the` tensioning device to any such modifications as fall within the truer spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A tensioning device for a lament comprising a bobbin having a wail defining a spool surface upon which the filament is wound and from which it is drawn, axle means rotatably supporting said bobbin, members within said bobl-vinv housed by said wall constructed andv arranged to be forced into frictional engagement, one member being nonrotatably attached to said wall but movable longitudinally relative to it and another being attached in a similar way to said axle means, means forcing said members into frictional engagement so as to resist rotation of said bobbin with a predetermined force. and means operated responsively to a predetermined high tension in said filament that is drawn from said bobbin for controlling the operation of said lastnamed means soA as to release said members and t assegnati` I. 3.

thereby permit said bobbin to rotate, and for causing the reengagement of said members to stop the bobbin when said tension fails below said predetermined value.

2. A tensioning device for a filament comprising a bobbin having a cylindrical wail forming a.

spooll surface upon which the filament is wound and from which it is drawn, an axle extending through said wall supporting it for rotation, a.v

pair of plates within said wall surrounding said axleone non-rotatably attached to said axle, but mounted for longitudinal movement with reference toit. and the other attached in a similar way to said wall, means holding said plates in trictional engagement to resist rotation of said '1l bobbin with a predetermined torce. an arm movably mounted with reference to said bobbin, said v arm having a part over which the iilament drawn from said bobbin is directed so that the arm is moved by increasing tension in the illament, and

connection means between said arm land saidj plate holding meansior operating'said means to. release said plate and thereby iree said bobbin when said arm is-moved apredetermined extent.

3. A tensioning device for a illament comprising a bobbin having a cylindrical wall forming a spool surface upon which the mament is wound and from which itis drawn, an axle extending through said wall supporting it for rotation, a plurality oi!l plates within said wall around Asaid axle, alternate ones oi' said plates being nonrotatably secured to said axle but tree to move longitudinally with reference'to it, and the others being similarly attached to said wall, a nut within said wall, a screw within said wall uponwhich l said nut is threaded, said screw forcing said nut to hold said plates in frictionai engagement to thereby resist rotation of said bobbin with a predetermined Iorce, an extension arm rotatable in the axis of rotation of said bobbin,'a member on said arm over which the filament fed from said bobbin passes so that the tension in the filament tends to rotate the arm in3-a predetermined direction, a spring resisting the rotation of said arm in said direction and said arm and s'crew having plates which interengage when said arm is moved by increased tension in said lament in said direction through'la predetermined arc and .upon further movementof said arm in said direction said plates turn said screw to operate said $5 nut to release said plates and thereby said bobbin.

- GEORGE LEITHISERQ 

